Explosive



Patented Aug. 12, 19 47 ZAZSJ a EXPLOSIVE Hartwell Henry Fassnacht,Wenonah, N. J., and Clifford Akeley Woodbury, Media, Pa., assignors toE. I. du Pont de Nemours & Company, Wilmington, Del., a corporation ofDelaware No Drawing. Application April 28-, 1943, Serial No. 484,862

4 Claims. 1

This invention relates to a new type of high explosive composition andmore particularly to a plastic composition possessing very desirableproperties.

The usual type. of plastic high explosive for commercial use comprisesthe gelatin dynamites, which are based on gelatinized nitroglycerin asthe principal explosive ingredient. Such explosives are excellentlyadapted for certain applications in that they possess high densities andconsequent high loading strength, fill the borehole compactly :becauseof their plasticity, and. have high water resistance. One drawback comesin the fact that such explosives, while possessing initial high velocityof detonation, do not retain this velocity after storage forconsiderable periods. of time.

Plastic explosives. of the above highdensity characteristics would bevaluable for military uses also, but it is essential there thatconsistently high velocity be attained in avery short intervalof timeeven with relatively small charges-and that such velocity be retainedeven after long period storage- Itwould" be desirablealso, insuch usesthat the explosive charge should be sufficiently insensitive to shockthat it'would be incapable of initiation by. a rifle bullet, forexample.

An object of thepresent invention is a plastic explosive compositionpossessing a high velocity of detonation and capable of retaining suchhigh velocity characteristics for a long periodof time. An additionalobject issuch an explosive that possesse'shigh strength and highdetonation velocity; A further object is a plastic explosive that isrelatively insensitive to shock. A still further object is an explosivecomposition containing tetryland nitroglycerin orother liquid nitrate'd;organic compound. Additional objects will be disclosed as the inventionis described more at length in the following.

We have found that the foregoing objects are attained by our invention,according to which the explosive composition contains a liquid-nitratedorganic compound capable of gelatini'zation with nitrocellulose, tetryland nitrocellulose. The liquid gelatinizable compound will in many casesbe nitroglycerin, 'but may include also materials dissolved innitroglycerin and; functioning as freezing point depressants. or.otherwise. Furthermore, the composition may-be free from nitroglycer-inand may comprise liquid nitrated compounds such as the aromaticnitrocompounds, for example a suitable blend of nitrotoluenes. Tetrylwill be present and will serve to give a'satisfactory degree ofsensitiveness to the compositions. The nitrocotton or other form ofnitrocellulose will be dissolved in the liquid nitrated compound andwill efiect gelatinization thereof, so that a desirable degree ofplasticity will be assured.

Mononitrotoluene Dinitrotoluene. Trinitrotoluene gitrocotton etr CalciumCarbonate- Velocity ofD etonation, M/Sec In the foregoing compositions,A contains nitroglycerin, with a certain amount of dissolveddinitrotoluene and a high percentage of tetryl. The compositions B and Care free from nitro-' glycerin and contain blends of mono-, di--, andtrinitrotoluene such as to make fluid mixtures capable of gelatinizationby means of the nitrocotton present. D and E are gelatinous compositionsof higher nitroglycerin content and free from nitrocompound's; E-representing a blasting gelatin type. All'the foregoing compositions-aresensitive to the action of a blasting cap, but the inclusionof'nitrocompounds in A,-B, and C rendered these incapable of'initiationby the impact of a rifle bullet. Such insensitive gelatinous"explo'sives would b'e desirable in military operations where relativelysafe but powerful demolition agents are desirable.

While the compositions cited have been such as to be'sensitive' totheaction of a commercial blasting cap, this degree of sensitiveness isriot essential. Our invention is intended to include alsocompositionsfof a lower degree of sensitiveness where not even se'veralblasting capstogether will-bring about detonation and where the action'of an intermediate booster charge of a powerful explosive is'necessaryiThe plastic explosives of our invention may Vary widely in'composition'.We'findit desirable in the case of nitroglycerin compositions, however,to employ between 5 and% nitroglycerin; 0.1 to 7.0% nitrocotton'; 7.0to;0% tetryl; and 0.1 to 1.0% calcium carbonate as an antacid material.When nitrotoluenes' or other nitrated compounds are used alongwith thenitroglycerin, they will replace aportion of this latter. When nonitroglycerin is present, the content 'of'nitro- 3 As has been stated,dissolved materials may be present in the nitroglycerin, and suchcompounds as tetranitrodiglycerin, ethyleneglycoldinitrate, nitratedproducts of higher aliphatic alcohols and aromatic nitrocompounds may beused for the pursugars, nitrochlorhydrins, nitration The abovecompositions are of the straight dynamite type, where tetryl replaces aportion of the nitroglycerin, where the percent strength is designatedby the nitroglycerin content, since no other explosive ingredient isordinarily present, In the case of compositions F and G, these pose ofinhibiting freezing, controlling sensitive-.

ness, etc. As nitrocompounds for use, we may employ nitrobenzene,nitrotoluenes, nitroxylenes, nitronaphthalenes, and the like. If suchnitrocompounds are used in the absence of nitroglycerin or other suchliquid explosive compounds, it is desirable that a liquid mixture beformed in which crystallization or freezing will not occur under widetemperature variations. A blend of nitrotoluenes of varying degrees ofnitration is suitable for such use.

Various forms of nitrocellulose are applicable as the gelatinizationagent for the liquid ingre dient, but nitrocotton of the type commonlyused in gelatin dynamites is very suitable. Small amounts ofgelatinization accelerants or plasticizers may be employed to control orimprove the qualities of the gelatins, for example dimethyl formamide,monoethylglycollate and the like.

The tetryl may be the typical grade in common use. In order to preventdustiness and unduly high sensitiveness of the dry ingredient, however,it will be preferable to employ a tetryl product coated with a smallamount of wax, oil, or grease such as a suitable petrolatum productapplied by any desired method. We may, for example, use tetryl having acoating of 0.1 to 5.0% of a parafiin hydrocarbon not fluid at ordinarytemperatures, i. e., having a melting point distinctly above thetemperatures encountered during storage and use of the explosive.

The compositions cited'in the foregoing examples are deficient in oxygencontent for complete combustion of the carbon and hydrogen to carbondioxide and water respectively. The large amount of carbon monoxideformedon explosion will make such explosives unsuitable for use inconfined places such as tunnels and underground metal mines. The matterof fumes is of less importance in many types of military applicationsand for certain commercial blasting. If an improvement in fumes isdesired, this may be accomplished by the inclusion of oxygen-supplyingingredients in the formula, for example sodium nitrate or ammoniumnitrate, in amounts sufiicient to effect complete combustion of carbonand hydrogen. The use of such oxidizing agents will be understood to beincluded within the scope of this invention.

The explosive compositions described in the foregoing have been of thegelatinous type where either nitroglycerin or other liquid nitratedorganic compound has been gelatinized by means of nitrocotton. Theinvention is intended to include also all nitroglycerin compositionscontaining tetryl to supplement the explosive force of hi. troglycerin.The following will serve as specific embodiments of such compositions:

may be considered as of 50% strength each, as tetryl is substantiallythe equivalent of nitro glycerin in strength at the oxygen balancesshown.

The explosives according to our invention have many outstandingadvantages. They possess the property of high velocity detonation, whichis retained for long periods of time even under adverse storageconditions. When explosion takes place, the explosives detonateconsistently at high velocities. They possess, also, high strength andhigh explosion pressures, good fragmentation capabilities, and excellentcutting and demolition properties. In addition, they are resistant tothe effects of Water and moisture and remain plastic over a widetemperature range (0-110" F.), so that they can be molded as desired.This latter property is important in demolition explosives. Along withtheir satisfactory sensitiveness to blasting caps, the preferredgelatins are insensitive to the action of rifle bullets and othersimilar impacts.

Our invention has been described fully in the foregoing, but it will beunderstood that many variations may be introduced in the compositions ofexplosives used without departure from the scope of the invention. Weintend to be limited only by the following patent claims.

We claim:

1. An explosive composition comprising 'between 5 and of a liquidnitrated organic compound taken from the group consisting of aliphaticliquid nitric esters and aromatic nitrocompounds, to 7% tetryl and 0.1to 7.1% nitrocellulose.

2. An explosive composition comprising between 5 and 85% nitroglycerin;0.1 and 7.0% nitrocellulose, and 89.8 and 7.0% tetryl.

3. The explosive composition of claim 2, in which at least a portion ofthe nitroglycerin has been replaced by an aromatic nitrocompound.

4. An explosive composition comprising a blend of nitrotoluenes inliquid form in the amount of 10 to 50%, between 0.1 and 3.0%nitrocellulose, and 40-90% tetryl.

HARTWEIL HENRY FASSNACHT. CLIFFORD AKELEY WOODBURY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

